Returns next cell or null if it is last cell in the grid.

<div class="definition">
     nextCell(index, colIndex, editable)
</div>

<div class="arguments">
    <table>
    <tr>
        <td>index</td>
        <td><b>integer</b>, record index</td>
    </tr>
    <tr>
        <td>colIndex</td>
        <td><b>integer</b>, column index</td>
    </tr>
    <tr>
        <td>editable</td>
        <td><b>boolean</b>, indicates if to return next editable cell</td>
    </tr>
    </table>
</div>
Returns { index, colIndex } object or null.

<h4>Description</h4>

This method returns you next cell or next editable cell It will advance to the next row if any. If there is no next cell, it
will return null. Will skip hidden columns.
<div style="height: 10px"></div>

The first argument <span class="argument">index</span> is the index in the <a class="method" href="w2grid.records">.records</a>
array. The second argument <span class="argument">colIndex</span> is the index in
the <a class="method" href="w2grid.columns">.columns</a> array.
<div style="height: 10px"></div>

If you have grid defined in the following way:
<textarea class="javascript">
let grid = new w2grid({
    name: 'grid2',
    columns: [
        { field: 'recid', text: 'ID', size: '50px' },
        { field: 'lname', text: 'Last Name', size: '30%', editable: { type: 'text' } },
        { field: 'fname', text: 'First Name', size: '30%', editable: { type: 'text' } },
        { field: 'email', text: 'Email', size: '40%', editable: { type: 'text' } },
        { field: 'sdate', text: 'Start Date', size: '120px', editable: { type: 'date' } },
        { field: 'edate', text: 'End Date', size: '120px', editable: { type: 'date' } }
    ],
    records: [
        { recid: 1, fname: 'John', lname: 'doe', email: 'vitali@gmail.com', sdate: '1/3/2012' },
        { recid: 2, fname: 'Stuart', lname: 'Motzart', email: 'jdoe@gmail.com', sdate: '2/4/2012' },
        { recid: 3, fname: 'Jin', lname: 'Franson', email: '--', sdate: '4/23/2012' },
        { recid: 4, fname: 'Susan', lname: 'Ottie', email: 'jdoe@gmail.com', sdate: '5/3/2012' },
        { recid: 5, fname: 'Kelly', lname: 'Silver', email: 'jdoe@gmail.com', sdate: '4/3/2012' },
        { recid: 6, fname: 'Francis', lname: 'Gatos', email: 'vitali@gmail.com', sdate: '2/5/2012' }
    ]
});
</textarea>

You can do:
<textarea class="javascript">
w2ui['grid2'].nextCell(5, 3, true);
</textarea>